There is a technique of changing an order of output data of a fast Fourier transform (FFT) unit to an order suitable for a latter circuit in order to reduce the power consumption of the latter circuit of the FFT unit. JP-A 11-298436 (Kokai) discloses a method of applying a de-interleaving process to output data of an FFT circuit to change the order of the output data to set an order suitable for a demodulating process by a latter stage. However, a large number of registers that hold values of the output data and selectors are necessary for a processing block that executes the de-interleaving process, and there is a problem that the circuit size increases.